Mitochondrial inheritance

In the September 6 Nature, Berlin and Ellegren from Uppsala University, Sweden, examine the controversial clonal inheritance theory for vertebrate mitochondrial DNA (mtDNA) by following co-inheritance of a female-specific nuclear DNA marker (Nature 2001, 413:37-38). They examined the avian W chromosome, most of which is non-recombining and therefore clonally transmitted by females. A polymorphic (CA)n repeat, NVHfp49, on the W chromosome of 53 female peregrine falcons (Falco peregrinus) and 1,625 bp of mtDNA sequence were followed. The patterns of divergence of mtDNA and W-chromosome sequences were completely concordant. These data support the hypothesis of clonal inheritance of mtDNA from mothers to daughters without recombination.